They're not particularly picky. I have my 5's, along with a Gallo sub, running off a Peachtree Decco. Their Nova, a significantly better unit, is available for $1k on their site now. Hybrid SS/Tube 80 wpc w/ built-in DAC, Class A fixed out, Class A pre-out, ESS Sabre DAC, 2 coax, 2 optical, USB, 3 analog inputs. Easy peasy.